In cellular wireless telecommunications a Femtocell is a part of cellular mobile network formed by a small cell having a typical range of operation on the order of 10 meters a small cellular base station. The Femtocell is a complement to the macrocell having a range on the order of several kilometers, microcell typically having a range of less than two kilometers, and picocell typically having a range of 200 meters or less. Its base station connects to the service provider's network via broadband connection (like for example digital subscriber line (DSL) or cable) and supports a limited number of active mobile terminals. A Femtocell allows service providers to extend service coverage indoors and in areas with limited or without any access. Known Femtocells are designed for wideband code division multiple access (WCDMA) although the concept is applicable to all standards including for example global system for mobile communications (GSM), CDMA2000, Time Division Synchronous Code Division Multiple Access (TD-SCDMA), WiMAX and long term evolution (LTE) networks. It can be used to solve the coverage and hotspot problem of the conventional macrocells, microcells and picocells. The typical usage area of a Femtocell is the indoor scenario such as office and residential buildings. The Femtocell base station, also called Femto Access Point, usually uses common internet connection as the backhaul forming a connection to a core network. As the coverage of a Femtocell is small, the transmission power of the Femtocell base station is relative low, usually less than 100 milliwatts (mW).
The demand on high speed wireless services increased rapidly during the last years. A major part of wireless services is provided in the indoor area such as offices, residences and campus buildings. As macro base stations usually have limited capacity and coverage performance in such areas, the service quality may be heavily impaired. In order to avoid a service declination, Femtocell base stations are deployed in the buildings where the access to macro cells is limited or unavailable. The Femtocell is regarded as a promising solution for indoor coverage problem and the employment of Femtocell base stations is becoming more prevalent. However, its comparatively low transmission power is in some scenarios also a limitation of the Femtocell base station. Because of the strong attenuation by walls and ceiling, the coverage of a Femtocell base station is usually restricted to one story and few rooms. In order to cover a service area in entire building, multiple Femtocell base stations have to be installed in dispersive locations.
For indoor communications, WLAN is the most popular technology for providing wireless access to indoor users. Similar to the Femtocell base stations, WLAN base stations also have to be placed in dispersive locations in the building in order to avoid coverage holes in the service range. Usually, Femtocell and WLAN are co-located in the same area to serve the different groups of wireless users, which may cause higher energy consumption, generate increased interference in the neighboring environment, and increase backhaul costs due to an exchange of more signaling data.